25 
Catenicellidae. The members of this family all growing in the 
form of free articulated colonies are mainly distinguished by the 
peculiar lateral chambers (loculi Busk) with which the zooecia are 
provided. Typically there are four such chambers to each free 
lateral wall. With the exception of the secoud (niimerated from the 
anterior part of the zooecium), in most species in^ more or less 
zooecia developed into an avicularium, the other three are keno- 
zooecia whose outer wall is wholly or partially uncalcified. The 
distal wall consists of a posterior horizontal and an anterior ascen- 
ding part of which the former as well as the wall between two 
neighbouring zooecia is provided with a group of single-pored ro- 
sette-plates. The named lateral chambers are also connected either 
with the zooecium or with one another by a number of single- 
pored rosette-plates. The ooecia which are in connection with a 
rudimentary distal wall and provided with an atrium are covered 
either by zooecia or by kenozooecia. A compose operculum. Here 
we shall only give definitions of the two chief genera: Catenicella 
(Blainv.) M. GilP) char. emend. The operculum with a straight 
or concave posterior margin; the front wall with 3—14 greater or 
lesser pyriform or oval non calcified spots (fenestrae); the front 
wall of the compensation-sac is protected by an inner, originally 
free, semielliptical, calcareous plate, rising from the posterior mar¬ 
gin of the orifice and distinctly visible through the fenestrae ^). 
In old zooecia the orifice is closed by a calcareous plate growing 
out from the line of union between the horizontal and the ascen- 
ding part of the distal wall. 
Caloporella M. Gill^) char. emend. The operculum with a 
convex posterior margin; the front wall without fenestrae, at the 
Tertiary Polyzoa of Victoria, Transact. Eoyal Soc. of Victoria Vol. IV, 
1895, pag. 8. 
2) This plate can be søen in Busks figure of Cat. plagiostoma in Cata- 
logue of marine Polyzoa, Part. 1; PI. V, fig. 1, 
Tertiary Polyzoa of Victoria, Transact. Koyal Soc. of Victoria Vol. IV, 
1895, pag. 8. 
